Nitrogenous condensation products



Patented Mar. 7, 1944 NITROGENOUS CONDENSATION PRODUCTS Paul Schlaok,Berlln-Treptow, Germany; vested in the Alien Property Custodian NoDrawing. Application September 27, 1940, Se-

rial No. 358,695. In Germany May 17, 1939 6 Claims.

This invention relates to new compositions of matter and moreparticularly to synthetic, nitrogenous, linear condensation products.

By action of diisocyanates on compounds with at least two functionalgroups reactive towards isocyanates such as oxyor amino groups polyamidecompounds are obtained which, when sufficiently polymerized yieldvaluable synthetic materials or synthetic resins. High molecular linearpolyurethanes are obtained, when equivalent portions of diisocyanatesare united with glycols, such as tetramethyleneglycol,decamethyleneglycol, xylyleneglycol or hydroquinone-pfldioxydiethylether. Polymeric ureas are formed in a similar manner withdiamines. Similar or identical compounds are also obtained, whendiurethanes are caused to react with glycols or diamines (U. S. A.patent application Ser. No. 277,948, filed June 7, 1939). Thesereactions are preferably carried out with urethane compounds in whichthe carbamic acid groups are esterified with an aromatic or enolichydroxyl compound, especially with phenols (U. S. A. patent applicationSer No. 352,550, filed Aug. 14, 1940) This invention has as an objectthe preparation of new and valuable compositions of matter, particularlysynthetic, fiber forming materials.

A further object is the preparation of filaments, fibers, ribbons, andfoils from these materials.

A further object is to form these materials by casting, dye-casting,injection molding or'pressing into useful articles.

A still further object is the manufacture of lacquers, coatingcompositions and impregnations for textile fabrics.

These and other objects will become apparent from the followingdescription.

It has been found that various novel polyurethane com ounds areobtained, which in their properties may deviate more or less from thosehitherto described with regard to hardness, melting point, solubilityand chemical reactivity, when diisocyanates and diurethanes (especiallywhen containing aromatic or enclic hydroxyl compounds linked inesterified form) are caused to react with biiunctional hydroxyl orsulfhydryl compounds, in which at least one of the functiona1 groupsshows alcoholic character, whereas the other may be present in the formof a carboxyl group, an amino group or a monosubstitutedv amino group.Furthermore the compounds must be chosen in such a way that at least onebifunctional compound reacting in substantial, prefers ablystoichiometricai quantity contains preformed amide groups (carbonamidegroups, urea groups, sulfamide groups, sulfonamide groups linked tocarbonaceous radicals), whereby compounds containing urethane groupsonly are excepted. The amide groups may be built into open chains or maybe constituents or heterocyclic rings beins built into the chain.Moreover, they may not only be present in one of the two reactants, inthe active (acylating) or in the passive (to be acylated) component, butsimultaneously also in both of them. The new possibilities obtainedhereby are various and a great variety is given in controlling theproperties of polyamide compounds according to the intended use.

According to the present invention there are condensed diisocyanates ordiurethanes with glycols, dimercaptans, amino alcohols, aminomercaptans, oxycarboxylic acids, mercapto carboxylic acids, of whichcomponents at least one contains performed amide groups. Polyamidecompounds are thus obtained, which show urethaneor thiourethane groupsbesides th preformed amide groups introduced by the starting material.For each linking they display at least one of these ester groups, when,as it is generally the rule, two homogeneous components are caused toreact with each other.

In principle one may work with more than two components. Besidesglycols, oxycarboxylic acids or amino oxy compounds containing alreadyan amide group, for instance a car-bonamide group, there may be presentfurthermor simple glycols,'oxycarboxylic acids or amino alcohols withoutsuch groups in the reaction mixture.

It is also within the scope of this invention, when dicarboxylic acids,for instance adipic acid, oxodibutyric acid or diamines, such ashexamethylene diamine and 'W-diamino dipropylether are present in partin the reaction mixture. Furthermore there may be added in partpolyamide forming compounds, such as amino carboxylic acids or saltsfrom diamines and dicarboxylic acids. Also these components or pair ofsubstances may contain amide groups in the molecule (according to U. S.patent application Ser. No. 348,683, filed July 31, 1940).

Besides the bifunctional components there may be added in minorquantities also polyfunctional compounds, for instance polycarboxylicacids with more than two carboxyl groups or their reactive functionalderivatives, furthermore, aminooxycarboxylic acids. Finally substancesmay be added for regulating the chainlength and influencing theelectro-chemical character of the end-product, which under the givenreaction conditions are capable to react 'on one side only, for instancemonovalent alcoing the condensation, if necessary, towards the end ofthe reaction. It is advantageous to work with two homogeneous reactivecomponents.

Polymeric compounds of uniform or at least regular structure are thenobtained, which for many purposes are more valuable than substancesobtained by direct condensation of more than three components. In thelatter case the course of reaction is very complicated, since the speedof reaction of the single components may vary considerably. Uniformly orregularly built substances differ more ro less considerably in importantproperties, for instance melting point and solubility, from thechemically isomeric mixed-condensates obtained when a mixture of thefinal hydrolysis products or their derivatives on which the polyamide inquestion seems to be based, is condensed.

Numerous methods may be employed for the synthesis of condensablecomponents which are applicable according to the present invention. Asfar as the starting material for the production of isocyanates ordiurethanes is concerned, the same diamino compounds with amide-likechain-interruption also come into question as described in U. S. patentapplication Ser. No. 348,683, filed July 31, 1940.

The conversion of these diamines into diisocyanates is accomplished inthe usual manner by action of the hydrochlorides on phosgen in anindifferent solvent which practically has so high a boiling point thatthe carbamic acid chlorides initially formed are decomposed by boiling.Also the urethanes, as far as they are not built up from a startingmaterial containing urethane groups are manufactured in a known manner,i. e. by the action of the diamines or their salts on halogen formicesters, for instance chloroformic acid phenyl ester, or as far as thearyl ester is concerned by the action of the free amines on thedlarylcarbonate, the latter being preferably employed in excess.

In as far as isocyanate compounds are employed it is useful to choosesimple components, since only such substances can be purified by theinexpensive method of distillation. Isocyanates of more complicatedconstitution are best obtained and worked up in solution, whereby thecontents of the solution may be easily found out by action of substancesyielding insoluble precipitation, such as aromatic amines.

In what various ways the components may be changed within the scope ofthe present invention can be seen from the following table. Theinvention is not limited to the types mentioned therein and to thesubstances described in these examples. Generally speaking the presentinvention relates to the manufacture of polyamides with urethane groupsfrom components which already possess, at least partly, preformed amidegroups.

TABLE Brmmcrrormr. Comormns Rsacrrvs WITH Dnso- CYANATES a Dnmsrrmnss(I) Glycols and diuretkanes (a) Compounds with amide groups in openchain.

( 1) HID-(CH2) r-NRr-CO(A)-- CO-N'R-(CHa) :-OH

az=at least 2, practically 3 or more, A=bivalent organic radical, may be=O.R=H or a monovalent, if necessary substituted hydrocarbon radical.

These compounds are obtained by the action of the dicarboxylic acids ortheir functional derivatives on amino alcohols, for instance oxalicacid, oxalic acid esters, adipic acid, adipic acid esters or adipic acidchloride. Suitable dicarboxylic acids are besides oxalic acid and adipicacid the following: malonic acid, glutaric acid, sebacic acid,oxodibutyric acid, oxalyl-bis-amino caproic acid, terephthalic acid,hexamethylenebis-oxamic acid dialkyl ester.

(2) Dimercaptanes according to Formula 1 are obtained from the aminomercaptanes by acylation with clicarboxylic acids or from the alkylamine halides, such as 3-chloropropylamine, and dicarboxylic acids withfollowing exchange of halogen. against sulfhydryl.

(3) Glycols and dimercaptanes with ureaor thiourca radicals.

HO-(CHz) ;-NRCO-NR(CH2) r410 (HS) (CS) (SH) x=at least 3, if necessary 4or more.

The compounds are obtained from the amino alcohols or amino mercaptanesby action of phosgent or carbonic esters or carbondisulflde orthiocarbonylchloride. The ureas are generally less valuable than theamides, since they have as a rule lower melting points. Instead of thesimple compounds with phosgen or thiophosgen there may be placed analkylene-bis-carbonyl group. It is possible, for instance, to combineamino alcohols or amino mercaptanes with a diurethane or with adiisocyanate, such as hexamethylenediisocyante. Components ofconsiderably higher melting point are thus obtained.

As described above the mercaptanes may also be obtained by the way ofalkylamine halides.

(b) Glycols (dimercaptanes with amide groups in heterocyclic rings).

( 1) Cyclic ureas and thioureas.

1); HO-(CHDr-N (CHI):

(2) Cyclic amides of the oxalic acid.

CHz-CH:

no-(ormr-n N-(CHi):-0K

:c=at least 2, preferably more than 3, obtained by the action ofdioxyalkyl ethylene diamines on oxalic acid diphenyl ester or otheroxalic acid compounds.

(3) 2,5-dioxopiperazine compounds.

(an) OER-CO N-icm),-on

CO-CHR R=alkyl, a:=2 or more, easily obtainable by reaction of the aminoalcohols with the a-halogen fatty acids, esteriiication and cyclizationof the amino esters or by the action of the amino alcohols on analdehyde, especially formaldehyde and hydrocyanic acid, esteriflcationof the nitrile and tanes on excess oxalic acid esters and saponiflcaano-(cnor-nn-cn-coon 1101 R nocm).-Nn-cn-coon 12011 :c=2 or more,obtainable from a-amino acids in the usual way.

Example.-Di-p-oxyethyl -diketopiperazine. (4) Glycols withoxaz'olrlnssno cmrN-cm-cn-cn-cm-N(cnm-onj These glycols are obtainedfrombivalent sulfo chlorides in a straight reaction, for instance byaction of trimethylene disulfochloride or benzene disulfochlorid onamino alcohols or amino mercaptanes. The mercapto group may also beintroduced through w-alkyl halide radicals. Ethane-disulfochloridecannot be used as component.

R=alky1 or substituted alkyl radical, R '=biva1ent organic radical,':v=two or more, preferably=3 or more.

Best obtainable by action of halogen alkyl sulfochlorides on diamines,for instance ethylene diamine, symmetrical dimethyl ethylene diamine,hexamethylene diamine with following exchange of the halogen against OKfor SH.

II. Oxy(mercapo) -carbon'ic acids :r=2, better 3 or more.

Action of the amino alcohols 0r amino mercaptlon of the oxamide acidesters thus formed.

a:=2, better or more, y=l or 3, better 4'or more. Obtainable by actionof the amino alcohols on excess dicarboxylic acid esters andsaponiiication oi the amide esters thus formed.

(3) HO-(CHzh-NR-CO- I v I NR--(CH2)w-COQH v (H8) x=2, better 3 or more,y=3 or more. Such compounds are obtainable for instance by action of theurethane amino acids or urethane amino acid esters on amino alcohols ormercaptoalcohois, which, it necessary, are afterwards saponifled.

' x=2, better 3 or more.

y=at least 2, preferably 4 or more.

(III) Aminooxy- (mcrcapto) compounds a:=at least 5. a1=2, preferably 3or more.

Compounds of this kind are obtainable by a reaction of the aminocarboxylic acid esters wanexcess amino alcohols or by the action of theamino acid chloride hydrochlorides on amino alcohols. Furthermore theycan be obtained by coupling of the amino alcohols with formyl aminocarboxylic acid chlorides and removing of the formyl group by boilingwith alcohol containing sulfuric acid.

The aiore-mentioned table is in no way exhaustive. It exhibits only thegeneral types of compounds adapted for the present invention and showsfurthermore by what general reactions they can be obtained.

If for instance in the table is stated, 1:2, preferably 4 or more, itmeans, that with compounds of the type a:=2 there are obtainedpolyamides which as a rule are not high polymeric or which possessmoderate thermal resistance only. Components of the type=4 or more,however, yield more stable and more valuable compounds, the condensationdegree of which may be increased considerably.

In the practical application of the reaction the components may bedirectly given together or melted together provided, the reaction is nottoo violent. If the latter is the case (with laccyanates) a solvent ordiluent is necessary, which at the end of the starting reaction can be.distilled oil?- immediately. Hydrocarbons for instance-and theirhalogen compounds are most suitable hereto, such aschloroform,tetrachloroethylene, benzene, chlorobenzene, o-dichlorobenzene, alsoethers, such as dibutyl ether, dioxane, dimethyldioxane and stableesters, such as butyl propionate. Instead of the indiiferent solvents ordiluents or together with those there may be employed also dissolvingcompounds containing hydroxyl- 0r amideor imide groups. These compoundsdo not yield substances which with isocyanates are stable at elevatedtemperatures. These are for instance phenols, such as phenol, n-cresol,xylenol, p-tertiary butylphenol and especially phenols negativelysubstituted by halogen, such as p-chloro-phenol or p-chloro m-cresol. Ofthe imide compounds there comes into question for instance carbazole.

The presence of phenols in the reaction mixture may influence thequality of the final product in a specifically optimal manner.Net-formations, which for instance may occur in the presence of ureagroups with H on the nitrogen atom, do not set in after addition ofphenol, or at least to a much smaller degree. Solvents may naturally beemployed, when a violent starting reaction is not to be expected, forinstance, when the reaction products melt only at high temperature beingnear to decomposition.

It is practical, especially when the reaction temperature lies above 150C., to cut off atmospheric oxygen, for instance by conducting a streamof nitrogen current over the reaction mixture. Generally speaking thepolyurethane amides are less oxidizable than linear polyamides, whichare obtained by condensation of carboxyl compounds with amines.

In order to work up the melt, liberated if necessary from the solvent bya vacuum distillation, it may be extruded through nozzles in the form ofa bristle or ribbon, preferably while cooling with water, if one doesnot prefer to spin the filaments directly from the primary melt. Ifsolvents being solid at room temperature, for instance p-chlorom-cresol,are used the solidified melt may be disintegrated and the solvent beremoved with a non-solvent for the polymer, such as methanol or acetone.The relatively low polymeric compounds thus obtained may be furthercondensed by reheating in the molten state, preferably in vacuo, until acertain viscosity is attained.

When recondensing the primary reaction products, it is oftenadvantageous to add small amounts, Minn- 760 moi. of a dicarboxylicacid, for instance adipic acid, sebacic acid, oxalyl-bisamino caproicacid. (U. S. patent application $81. No. 348,683, filed July 31, 1940.)Such admixtures suitably dosed facilitate the formation of a higherpolymerization degree, provided the reactive groups in the reactionproduct are not lost by oxidation or other side-reactions.

Polymers, which before recondensation are to be precipitated, arepractically treated in the presence of a small amount of a phenol, inorder to maintain the reactivity. V

Finally the primary reaction products may be dissolved in a solvent notused during the condensation, such as formic acid or acetic acid, andmay be precipitated again from this solution by adding non-solvents orby discharging them into non-solvents. By a suitable choice of thequantitative proportion of solvent and precipitant, there may beaccomplished simultaneously a purification or fractionation. Theproducts according to the present invention are of wide use. Decidedlyhigh polymeric compounds are valuable starting materials for formedstructures. They may be worked up in the thermoplastic or plasticisedstate, from the melt or from solutions, for instance in phenols, formicacid, acetic acid, in some cases also alcohols into filaments, ribbons,bristles. foils, and films. Furthermore they may be formed by casting,dye-casting, injection molding or pressing in any desirable manner.Substances of a medium polymerization degree are suitable for themanufacture of lacquers and coating compositions or for impregnation,especially of textiles. Water soluble products may be used as protectivecolloids. Generally speaking they may be employed as auxiliary agents inthe different branches of the textile industry and also in the relatedbranches of chemical technilogy, for instance in the paperand leatherindustries.

EXAMPLE I To a solution of two mols 3-amino propanol in alcohol there isadded, while cooling, one mol oxalic acid dimethyi ester in as littlemethanol. as possible. The symmetrical dl-3-oxypropyl-oxamide (F. P. C.)is hereby formed in very good yield. To the diamide dlmolved in m-cresolat elevated temperature there is given the corresponding amount ofhexamethylene diisocyanate. The mixture is gradually heated up at (2.,while stirring, and kept at this temperature for 3 hours, wherebyatmospheric oxygen is excluded.

The solution after cooling is precipitated with dry acetone. The productwhich is thoroughly washed with acetone is remelted in a nitrogenatmosphere and heated up at 230 C. for 3 hours under 1 mm. pressure,whereby part of the cresol is distilled off. The polyurethane meltstowards 0. The melt can bespun directly. a product being also spinnableis obtained, if the dioxypropyl oxamide is suspended in benzene, part ofthe benzene for elimination of the last traces of humidity is distilledoff and if the exactly calculated amount of hexamethyiene diisocyanatein water-free benzene is added and the mixture boiled for 2 hours underreflux. The benzene is then distilled off and the residue still heatedup at 240 C. for 3 hours in vacuo of 1-2 mm.

EXAMPLE II 1 mol hexamethylene diamine is added to excess oxalic aciddiethyl ester (4 mols in the same volume of alcohol). Thehexamethylene-bisoxamic acid ethyl ester (F. P. 80 C.) is precipitatedin colorless plates. 1 moi of it is dissolved in warm alcohol and thereare added 2 mols of 3- amino propanol. Theww'-di--y-oxypropylhexamethylene-bls-oxamide (F. P. at about 195) thusobtained in good yield is heated with the equivalent amount orhexamethylene-bis-carbamic acid diphenyl ester at ISO-180 C. in anitrogen atmosphere. After 3 hours the pressure is gradually reduced to2 mm. and the temperature flnally increased at 240 C. The temperature of240 C. is kept 23 hours. The polyurethane amids] thus obtained probablyof the following form a COCO-NH(CH:)3O] cant be spun into filamentsdirectly from the me EXAMPLE III 3-amino propanol hydrochloride isshaken for 6 hours with the calculated amount of formaldehyde andpotassium cyanide in the presenc of ether thus forming3-oxypropyl-sarcoslne nitrile. This is saponiiled with methanolichydrochloric acid into the methy1 ester and the ester thus liberated isthen heated at ISO-170 C. for about 4 hours in phenol. It is cyclicizedhereby to NH- bis-3-oxypropyl-dioxypiperazine. This (1 mol) is dissolvedin three parts of o-chloro phenol, traces of water are distilled off byadding a small amount of benzene. The exactly calculated amount ofoctamethylene diisocyanate (1 mol) dissolved in benzene is then added.After heating at 80 C. for one hour th temperature is first bis-carbamicacid diphenyl ester for one hour at 150 C., then gradually at 180 C.under re-" raised to 150 C., whereby the main amount of benzene distillsoh, and finally to 200 C., where it is kept for 3 hours. The polyamideis then precipitated by adding water-free acetone whichNN'-di-5-oxypentylurea obtained by action of 2 mols 1-amino-pentanol-5on 1 mol diphenyl carbonate at 100 C. i dissolved in dry dioxane in apressure vessel and there is added to the solution the calculated amountof tetramethylene diisocyanate. After the reaction is over the vessel issealed and heated at 240 C. for 3 hours. The solvent is gradually blownoff at this temperature and the product is heated finally still 1 nhours in vacuo (2 mm.) under a nitrogen current., The melt is thenextruded in cold water through a slot. The polyamide is obtained intheform of a, thick, elastic, very flexible ribbon.

EXAMPLE V e-bI'OIllO caproic acid chloride (obtained by action of thee-bromo caproic acid on thionylchloride, the e-blOlIlO caproic acidbeing obtained from e-amino caproic acid and nitrosylbromide) is coupledin alkaline solution with e-amino caproic acid and the bromide isreplaced by hydroxyl by boiling with potassiumformiate in 70% alcohol.The w-oxycapronyl caproic acid is united with the equivalent amount oftetram'ethylene diisocyanate in tetrachloroethylene.

After the initial reaction is over, the mixture is boiled for one hourand the-solvent distilled off. The residue is gradually heated until190-200 C.

, finally in vacuo (about 2 mm.). After 5-6 hours the product isspinnable from the melt.

EXAMPLE VI N-methyl-3-chloropropyl amine hydrochloride is converted withsulfurylchloride in carbon tetrachloride into the N-sulfo chloride andthis is coupled with an alkaline solution of e-amino caproic acid. TheN-w-chloropropyl sulfamide- N'-e-C8.Pl'0i0 acid is saponified by boilingwith excess potassium formiate in 70% alcohol. The hydroxy acid thusobtained of the formula HOCH2CHzCH2 TTS02-:NH-(CH2)5CO0H OH:

is caused to react with the equivalent amount oftetramethylene-bis-carbamic acid diphenyl ester by heating at 100-190"C. finally in vacuo. The temperature is raised so thatv 180 C. arereached within two hours. It is then heated another 3 hours at 180-190C. By remelting of the reaction product liberated from the Phenol bydisintegrating in acetone the polymerization degree may be increased byfurther splitting off of phenol in vacuo.

EXAMPLE VII 1 mol trimethylene disulfochloride is coupled at 0 inaqueous solution with 3-amino propanol. TheNN'-di-).-oxypropyltrimethylene disulfamide thus precipitated is heatedwith tetramethyleneduced pressure and finally at 220 C. A tough resin isobtained which in solution, for instance 3-chloropropylainine iscondensed in an alcoholic solution of methyl amine intodi-(A-aminopropyhmethylamine. The free amine is discharged into a 60 C.hot solution of excess diphenylcarbonate in benzene. Hereby the di-N-propylmethylamine-3-3'-carbamic acid diphenyl ester is obtained. Bycondensing the same for 4 hours with lw-dioxypropyl oxamide at 160-. 180C. in a nitrogen current a condensation product is obtained. which iseasily soluble in acids and which precipitates high'molecular compoundswith acid groups, such as dyestuffs and tanning matter. By alkylationwith dimethyl sulfate the tertiary amine groups may be converted intoquaternary ones. The aqueous so so lution of the methylated productsalso precipitates dyestuifs and tanning matter.

EXAMPLE IX The NN-di-A-oxypropyl-ethylenediamine ob tained bycondensation of ethylene bromide with excess 3- o propanol is convertedby means of thiophosgen into the cyclic thiourea. By the reaction ofthiourea with asolution of the equivalent amount of hexamethylenediisocyanate in dioxane and boiling of the reaction mixture for 40 3hours a polyurethane is obtained, which becomes water-soluble by a.treatment with alkylating agents, such as dimethylsulfate,benzylchloride or chloroacetic diethylamide. The aqueous solutionprecipitates tanning matter and dyestuffs with acid groups. By an alkalitreatment the alkylated product becomes again water-unsoluble bysplitting oil the sulfur groups.

EXAMPLE X 3-amino propanol is acylated in aqueous 30% solution byshaking with terephthalic acid chloride in ether. Theterephthaloyl-bis-aminopropanol (F. P. 187 C.) thus obtained iscondensed with the equimolecular amount of hexamethylene-bis-carbamicacid xylenyl ester (from hexamethylenediamine and the chloro formic acidester of technical xylenol) in xylenol for 8 hours at l80-220 C. and thepolyurethane amide is finally precipitated with acetone. By remelting ofthe product purified with acetone and by an after-condensation shortlyabove the melting temperature during 4 hours at 2 mm. the degree ofpolymerization is increased.

I A similar product of lower melting point is obtained fromadipinyl-bis-arnino propanol (obtained from adipinylchloride andpropanol amine,

F. P. 128 C).

EXAMPLE ICE Naphthalene tetracarboxylic acid dianhydride 7o is condensedin di-chlorobenzene with 2 mols 5- amino pentanol-l. Thebis-NN'-w-oxypentylnaphthalene-tetracarboxylic acid cliimide thusobtained is mixed with octamethyleneebis-can bamic-p-chlorophenyl ester(obtained from the to diamine with chloro formic acid p-chloro nhenylester) by adding of /100 mol isooctylphenollithium (calculated on thediimid)- The mixture is first heated for 1 hour at 150 C. by adding of 2parts of p-chlorophenol and then for 9 hours at 190-200 C. The masssolidified after cooling is then disintegrated and liberated from thep-chlorophenol by extraction with acetone. By remelting in vacuo thepolymerization degree of the product may be increased.

EXAMPLE XII 3-amino propanol is shaken in benzene with e-amino caproicacid chloride-hydrochloride (prepared from the amino acid according tothe method of Emil Fischer). e-aminooaproyl-3- aminopropanol is formedhereby in good yield. The amine freed from the hydrogen chloride iscondensed with tetramethylene bis carbamic acid diphenyl ester byheating for hoursat 180-240 C., at the end under 2 mm. The polyamidethus donned is spinnable into filaments directly from the melt.

EXAMPLEEII 1 mol 3-mercaptopropyl amine sodium is caused to react inalcoholic solution with it moi oxalic acid diethyl ester. Thedimercaptane isolated under exclusion of oxygen is heated at 180 C. withhexamethylene-bis-carbamic acid diphenyl ester and is kept at thistemperature for 10 hours. After cooling the melt is dissolved in formicacid and the polyamide precipitated as yellow powder by means ofacetone.

EXAIdPLE EV 3-amino propyl mercaptane sodium is caused to react inalcoholic solution with excess oxalic acid diethyl ester. The 3-mercaptopropyloxamide acid obtained by saponification with alkali is condensedby heating for 8 hours into a polyamide at 120-190 C. with theequivalent amount of hexamethylene-bis-carbamic acid di-p-cresol ester.

EXAMPLE XV phenyl ester.

assasoe 'the reaction temperature is kept below C. within the firsthour. Th mass is then boiled tor 4 hours and the solvent distilled off.Also this product can be dissolved and reprecipitated from iormicacid.By an often-condensation of the melt being liberated from solvents thepolymerization degree may be increased.

A similar but higher melting product is obtained by employingadipinyl-bis-amino phthalic acid-'y-oxypropylimid instead oi the sebacicacid compound.

EXAMPLE XVI Lysine anhydride is converted into the dicarbamic ester bymeans of chloro carbonic acid 1 mol oi! it is heated for 2 hours at C.with 1 mol decamethyleneglycol. The phenol formed thereby is distilledofi. in vacuo. After further heating for 6 hours at 180-200 C.- a toughresin is obtained which solidifies after cooling into a hard mass.

What I claim is:

1. A process for the production or nitrogeneous linear condensationproducts which comprises subjecting to condensation conditions adiurethane with a bifunctional compound of the for-- I mula:

wherein X is selected from the group consisting or O and S, :r is atleast 2, and Y is a bivalent radical selected from the group consistingof COCO and --CO-R-CO, wherein R is a bivalent hydrocarbon radical.

2. Nitrogeneous linear condensation products obtained by the process setforth in claim 1.

3. The process as defined in claim 1, wherein said biiunctional compoundis a glycol.

4. The process as defined in claim 1, wherein said biiunctional compoundis a dimercaptan.

5. The process as defined in claim 1, wherein R is a bivalent aliphatichydrocarbon radical.

6. The process as defined in claim 1, wherein Y is the oxalyl radical.

PAUL SCHLACK.

